Shaft-positioning apparatus



1949- R. c. MARHOLZ' 2,477,995

SHAFT-POSITIONING APPARATUS Filed April 28, 1945 2 Sheets-Sheet 1 J50.15b I INVENTOR. Md C 017L043,

BY Mk f/Wao 9- R. c. MARHO LZ 2,477,995.

SHAFT-POSITIONING APPARATUS Filed April 28, 1945 2 Sheets-Sheet 2INVENTOR.

Patented Aug. 2, 1949 Richard C. Marnom'chiea o, 111., asslgnor toBelmont Radio Corporation, Chicago, 111., acorporation of Illinois IApplication April 28, 1945, Serial No 590,890

11 Claims. (Cl. 287-52) 1 This invention relates to shaft-positioningapparatus and, while it is of general application, it is particularlysuitable for positioning the shaft of the tuning apparatus of aradio-broadcast receiver, that is to a so-called mechanical tuner, andit will be described in such an application;

Heretofore there have been devised numerous mechanical tuners forradio-broadcast receivers of a wide variety of types. In general, atuner of this type comprises a rotatable shaft, usually an extension ofthe shaft of the tuning condenser, and a plurality of shaft-positioningmembers or cams, one for each of a group of stations to which thereceiver is adapted to be tuned. Each cam or member is locked to theshaft in such a pre determined angular position that, when a camactuator is brought into engagement and pressed to the point on the camof minimum radius, the associated condenser tunes the receiver to thestation corresponding to soon cam and cam actuator.

' When initially setting up such a mechanical tuner or when resetting itto adapt it to be mechanically tuned todifierentstations, either in thesame or different localities, there is presented the problem ofreleasing the several locking members for individual adjustments to newangular positions independently of each other. It is preferable to beable to effect this release readily from the front of a broadcastreceiver cabinet and with only a moderate amount of actuating force and"that the releasing mechanism be simple" and inexpensive in constructionand reliable in operation. The prior art mechanical tuners have leftmuch to be desired in this respect.

It is an object of the invention, therefore, to provide a new andimproved shaft-positioning apparatus which overcomes the above mentioneddisadvantages and imitations oi the prior art apparatus of this type.

It is another object of the invention to provide a new and improvedshaft-positioning apparatus including simple and inexpensive provisionstor releasably locking one or more of the shalt-positioning members inany desired relative angular position or positions.

It is a further object oil the invention to pip vide a new andimprcvedshaft-positionnig apparatus applicable to the mechanical tunersoi broacast receivers including novel provisions for releasably lockingthe several. shaft-positioning members from the front oi the receivercasing.

In accordance with the invention, shaft-posiitioning apparatus comprisesa rotatable shaft having a recess therein and a shaft posltiontns memberrotatably mounted on the shaft and at least partially coveringtherecess. The apparatus also includes means for releasably locking the;shaft to the memberin any, desired angular position, including aresilient deformable look-,- ing membervdisposed in therecess and meansfor deforming the locking member to engage the po sitioning member. 7Further inaccordance with the invention, positioniug apparatus comprisesa. rotatable shalt, a plurality of axially spaced shaft-positioningmembers rotatably mounted'on the shaft, andan elongated axiallyadjustable locking means including a plurality of portions individuallyengaging the members for locking and releasing the members with respectto the shaft. For a bctter understanding or the invention, together withother and further obiects thereof, reference is had to the icllowmgdescription taken in connection with the accompanying drawingswhlle itsscope will be pointed out in the appended claims.

- Referring now to the drawings, Fig. 1 is a view in front elevation,Fig, 2 a bottom view,- and Fig. 3 is a view or a mechanical tuner for abroadcast receiver incorporating the shait-positionini apparatus or theinvention taken on line 3-4 oi; Fig, 2; 4 is a fragmentary explodedperspective View of one of the Shaft-positioning members oi thestructure or Figs. 1-3, inclusive, audits associated locking means;Figs. 5 and 6 are vertical and horizontal longitudinal sectional views01 the releasable locking means or the structure oi Figs, 1-3,inclusive; whileFiss. 7 and a are longitudinal sectional views and crosssectional views, respectively, of a modified form of re leasable lockingmeans suitable for embodiment inqthe mechanical tuner of Figs. 1-3,inclusive. Reierringnow more particularly to Figs. 1, 2 and 3 of thedrawings, there is represented a shait-positiomng apparatus embodyingthe in.- vention as applied to a mechanical tuner oils radimbroadcastreceiver. The tuning mechaper so, may be of any conventional type and isillustrated, by was of example, as including a pair of adjustablertuningcmdensers 1M and H mounted on a common shalt l2 forum-control, the shaft92 being iournaled in. a U-shaped Home It. The positioning apparatusalso incmdesqa hollow rotatable shalt which may constitute eitheranextension or the condenser shalt it or a separate shalt connectedthereto in am] suit abletashicn. The shatt to is provided with .aplurality oi axially spaced circumierential receases a each having: apair of diametrically a series of spacing washers Ila-He, inclusive,-

keyed or otherwise secured to the shaft against rotation to permitindependent positioning of the several cams l5a-I5f, inclusive. Each ofthe hubs Mia-I61, inclusive, at least partially and. preferablycompletely individually covers its respective one of the recesses [4aand the apertures Mb in the shaft I4.

The positioning apparatus also includes a plurality of cam operators,such as push buttons l8ol8f, inclusive, pivotally mounted on a shaft l9and biased out of contact with their respective cams by a series ofaxial springs, such as the spring I90 (Fig. 3).. The buttons l8al 8project through apertures in the front wall of the receiver cabinet 24.The cams l8a-l8j, inclusive, are provided with actuating rollers 20o20f,inclusive, respectively, for actuating their respective cams to set theshaft [4 when locked to the cams,

and thus the condenser shaft [2, into predetero mined angular positionscorresponding to the positions of the tuning condensers I and Ilrequired to tune the receiver to the preselected broadcast stations. Theshafts l4 and I9 are suitably mounted in a frame 28 secured to the frameI3 or forming an extension thereof.

The positioning apparatus also includes an elongated axially adjustablelocking means including a plurality of portions individually engagingthe positioning members .or cams I8a--l8f, l;

inclusive, for locking and releasing them with respect to the shaft [4.Specifically, this locking means comprises a plurality of lockingmembers 2la-2 I j, inclusive, (Figs. 4, 5 and 6) individually interposedbetween the positioning cams [So-- inclusive, and the shaft M forindividually releasably locking the positioning cams to the shaft in anydesired relative angular positions. As shown most clearly in Fig. 4,each of the locking members, for example the locking member 2 la,comprises a resilient deformable member disposed in one of the recesses,such as the recess 14a, and is preferably in the form of an annularexpansible member such as a split sleeve, as shown, of an undeformedouter diameter equal to or slightly less than that of the shaft I4 andof a thickness somewhat greater than the shaft l4 so that the portions2la1 and 21m adjacent the split project inwardly through the aperturesMb on the opposite sides of one of the bars 140. The member 2 laopposite the split has a longitudinal recess 2 lag, which is adapted toengage the other of the bars Mc joining the adjacent shaft sections sothat the member 2la will fit smoothly within the cylindrical recess Ma.By cutting the recess 2| as' in the sleeve 2la, it is also made somewhatmore flexible to facilitate its deformation.

The positioning apparatus also includes means for deforming the lockingmembers 2Ia--2If, inclusive, individually to engage their respectivepositioning cams l5a-l 5f, inclusive, to lock them to the shaft. Thisdeforming means constitutes an elongated axially adjustable member 22shown as a U-shaped or channel-shaped element of stamped sheet metal.The member 22 is disposed within the hollow shaft M for rotationtherewith and is provided with a plurality of upstanding wedgingportions 22a-22f, inclusive, which are adapted to engage the inwardlyprojecting portions of the split locking sleeves 2la2 I ,f, inclusive,for actuating or deforming the same to release or lock their respectivepositioning cams l5a -l 5f, inclusive; that is,' the axially adjustableelongated member22 and its associated'upstanding portions 22a,22j,inclusive, constitute adjustable camming means engaging and spreadingthe several split-sleeve locking members 2 la2 If, inclusive.

As stated above, it is desirable in mechanical tuners to which thepositioning apparatus of the invention is applied to be able to lock orrelease the several positioning cams from the front of the receivercabinet. To this end, there is provided an operating knob 23 extendingthrough the front wall 24 of the receiver cabinet and mounted on anaxially adjustable shaft 23a having thereon a circumferentially groovedcollar 23b engaging one arm of a bell crank lever 25 pivotally mountedat 25a in the frame 28. The other arm of the bell crank 25 is connectedto a circumferentially grooved collar 26 secured to an extension 225/ ofthe member 22. Also mounteclon the shaft 23a of the knob is an elongatedpinion 23c engaging a crown gear 21 mounted on the shaft I4.

It isbelieved that-the operation of the shaftpositioning apparatus ofthe invention will be clear from the foregoing description. In brief,assume that it is desired to change the setting of one of theshaft-positioning members, such as the cam [5a, to effect a tuning ofthe receiver upon the depression of the cam operator l8a to a differentbroadcasting station. The knob 23 is pushed in, actuating the bell cranklever 25 to adjust the member 22 to the right, as illustrated in Fig. 2,thereby withdrawing the camming portions 22a--22f, inclusive, of themember 22 from the split sleeves 2Ia2lf, inclusive, so that the sleevescontract the portions thereof adjacent their respective splitsprojecting inwardly through the apertures Mb in the shaft 14.Positioning cams [Ea-45f, inclusive, are then free to be rotated underthe control of their respective buttons l8al8f, inclusive.

The adjusting knob 23 is then turned to rotate the shaft l4 through thegearing 23c, 27 to adjust the tuning condensers I0 and H to tune thereceiver to the desired broadcasting station. With the knob 23 retainedin this position, the camoperating button la is depressed and its rollerZlla engages the positioning cam l5a, rotating it on the shaft 14 untilthe roller 20a rests in the depression in the cam, that is at the pointof the cam of minimum radius. During this resetting of the cam l5a, theother cams l5b-l5f are undisturbed due to the interposed spacing washersIla-4 1e, inclusive, which are secured to the shaft it against rotation.The adjusting knob 23 is then pulled outwardly, without rotating it,thereby actuating the bell crank lever 25 in a clockwise direction andforcing the member 22 to the left as illustrated in Fig. 2 so that itsseveral camming portions 22a-22f, inclusive, re-engage the split sleeves2|a2lf, inclusive, expanding or deforming them to re-engage theirrespective positioning cams I5a-l5,f, inclusive. Obviously, a resettingof any of the other positioning cams l5b-l 5f, inclusive, is effected bya similar operation.

Thus, it is seen that there is provided a single means, that is theadjusting knob 23, operable from the front of the receiver cabinet 24,for axially adjusting the locking means comprising the member 22 and thesplit sleeves Zl-a -Z-lf', inclusive, to lock or release the positioningearn-s lira-l), inclusive, with respect to the shaft l4 and also forrotating the shaft I4 to tune the receiver to any desired broadcastingstation as a step in resetting the positioning cams lbw-Hi,

inclusive.

In Figs, '7 and 8 is rep-resented a modified form of the locking meansof the invention. In this arrangement, a hollow rotatable shaft 3-4; isprovided with a series of segmentalcircumferential apertures him-E ie,inclusive, the adjacent sections of the shaft being joined by segmentalportions such as the portions 3 37. Within the segmental apertures aredisposed a plurality of annular spring-locking members tfiatte,inclusive, which, as shown in Fig. 8, are ribbed or corrugated so thatthey substantially fill the segmental apertures 3 iaf.de, inclusive, butare interrupted by the segmental shaft portions 3d In this case, theelongated axially adjustable member is in the form of a solid shaft 31having a series of enlarged portions "la-31c, inclusive, which whenpositioned to engage the spring locking members 35a--85e, inclusive, areeffective to deform or expand them to engage or grip their respectivepositioning cams Elia-45c, inclusive. In all other respects, theoperation of the positioning apparatus including the locking means ofFigs. 7 and 8 is similar to that describing the operation of thepositioning apparatus of Figs. 1-6, inclusive, and need not be repeated.

While there have been described what are at present considered to be thepreferred embodiments of the invention, it will be apparent to thoseskilled in the art that various changes and modifications may be madetherein without departing from the spirit or scope of the invention.

What is claimed as new is:

l. Positioning apparatus comprising, a rotatable shaft having a recesstherein, a shaft-positioning member rotatably mounted on said shaft andat least partially covering said recess, means for releaeably lockingsaid shaft to said member in any desired relative angular positionincluding a resilient deformable locking member di posed in said recess,and means for deforming said locking member to engage said positioningmember.

2. Positioning apparatus comprising, a hollow rotatable shaft having anaperture therein, a shaft-positioning member rotatably mounted on saidshaft and at least partially covering said aperture, and means forreleasably locking said shaft to said member in any desired relativeangular position including a resilient deformable locking memberdisposed in said aperture, and means for deforming said locking memberto engage said positioning member.

3. Positioning apparatus comprising, a hollow rotatable shaft having anaperture therein, a shaft-positioning member rotatably mounted on saidshaft and at least partially covering said aperture, and means forreleasably locking said shaft to said member in any desired relativeangular position including a resilient deformable locking memberdisposed in said aperture, and axially adjustable means disposed withinsaid shaft for deforming said locking member to engage said positioningmember.

4. Positioning apparatus comprising, a hollow rotatable shaft having anaperture therein, a shaft-positioning member rotatably mounted on irotatable shaft having a circumfere 6.. said'shaft and at leastpartially covering aperture, and means for releasably locking s shaft tosaid member any desired relative angular position including an.annuliai' expansrb locking member including a portion project i inwardlythrough. said aperture, and means for expanding said locking member toengage said positioning member.

5. Positioning apparatus compris' and an aperture therein, ashaft-positic ber rotatably mounted on said shaft and at partiallycovering said recess, s fer i1ele'asabl y locking said shaft to said inY desired relative angular position inclu silient deformable lockingmember (1 posed in said recess and having a portion projecting: in.-wardily through said aperture, and axially ac justable means disposedwithin said shaft for engaging said projecting portion of said lockingmember to deform the same, thereby to engage said positioning member.

6. Positioning apparatus comprising, a hollow rotatable shaft having acircumferential recess and an aperture therein, a shaft-positioningmember rotatably mounted on said shaft and at least partially coveringsaid recess, and means for releasably locking said shaft to said memberin any desired relative angular position including a resilient splitsleeve disposed in said recess and having a portion projecting inwardlythrough said aperture, and axially adjustable camrningmeans disposedwithin said shaft to engage the split in said sleeve to expand the same,thereby to engage said positioning member.

'7. Positioning apparatus comprising, a hollow rotatable shaft having asegmental circumferential aperture therein, a shaft-positionin memberrotatably mounted on said shaft and at least partially covering saidaperture, and means for releasably locking said shaft to said member inany desired relative angular position including 'a resilient annularspring locking member disposed in said aperture, and an axially movablecamming member disposed within said shaft to expand said spring lockingmember, thereby to engage said positioning member.

8. Positioning apparatus comprising, a rotatable shaft, a plurality ofaxially spaced shaftpositioning members rotatably mounted on said shaft,a plurality of members for individually releasably locking saidpositioning members to said shaft in any desired relative angularpositions, and an elongated axially adjustable member engaging saidlocking members for actuating and releasing the same to release or looksaid positioning members with respect to said shaft.

9. Positioning apparatus comprising, a rotatable shaft, a plurality ofaxially spaced shaft-posttioning members rotatably mounted on saidshaft, a plurality of locking members individually interposed betweensaid positioning members and said shaft for releasably locking saidpositioning members to said shaft, and an elongated axially adjustablemember engaging said locking members for actuating and releasing thesame to release or lock said positioning members with respect to saidshaft.

10. Positioning apparatus comprising, a rotatable shaft having aplurality of axially spaced recesses therein, a plurailty of axiallyspaced shaft-positioning member rotatably mounted on said shaft and atleast partially individually covering said recesses, a plurality ofresilient deformable locking members individually disposed 7 in saidrecesses, and an elongated axially adjustable member engaging saidlocking members for actuating and releasing the same to release or looksaid positioning members with respect to said shaft.

11. Positioning apparatus comprising, a hollow rotatable shaft having aplurality of axially spaced apertures therein, a plurality of axiallyspaced shaft-positionin members rotatably mounted on said shaft and atleast partially individually covering said apertures, a plurality ofresilient deformable locking members individually disposed in saidapertures, and an elongated axially adjustable member disposed withinsaid shaft and engaging said locking members for actuating and releasingthe same to release or look said positioning members with respect tosaid shaft.

RICHARD C. MARI-IOLZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

